This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Considerable research has focused on the relationship between glucocorticoid levels and cognitive performance. In humans, high levels of cortisol produced by stressors or by administration of glucocorticoids have deleterious effects on declarative memory, face recognition memory, and working memory. However, there is little research on the impact of reduced stress reactivity on cognitive performance. Such research requires either reducing glucocorticoid levels experimentally or studying populations with lower stress reactivity. We have previously shown that monkeys with SIB have lower stress reactivity than controls. Thus, they provide an important model to test whether naturally occurring lower stress responsiveness is associated with increased performance in rhesus monkeys.